<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            width: 800px;
            height: 300px;
            background-color: pink;
            display: flex;
            /*默认的主轴是 x轴 行 row 那么y轴就是侧轴喽*/
            /*我们的元素是跟着主轴来排列的*/
            /*flex-direction: row;*/
            /*简单了解 翻转*/
            /*flex-direction: row-reverse;*/
            /*我们可以把我们的主轴设置为 y轴 那么 x轴就成了侧轴*/
            flex-direction: column;
            /*flex-direction: column-reverse;*/
        }
        span{
            width: 150px;
            height: 100px;
            background-color: skyblue;
        }
    </style>
</head>
<body>
<div>
    <span>1</span>
    <span>2</span>
    <span>3</span>
</div>
</body>
</html>
